LIPIDS

Lipids

Triglycerides fats and oils

Phospholipids Sterol derivatives

Storage

Adipose tissueFat storingCan expand indefinitely

by number by size

Lipids

Provides energy stored fat supplies 60% of energy

during rest prolonged exercise starvation

Lipids

Provide insulation vital organ protection nerve impulse transmission

Cell structure Enhance fat soluble vitamin

absorption

Lipids

Facilitate weight gain Found in plants and animals Visible and invisible (hidden) fats Body synthesizes all fatty acids

except two 9 kcal/g

Lipids

Supply taste and flavor to foods Post-prandial satiety

Can stay 3 - 4 hours in stomach

Lipids

Precursor for synthesis of steroid hormones prostalandins and actylcholine

Triglycerides

Fats and oils 95% of total fat intake 3 fatty acids attached to 3 carbon

based glycerol Glycerol is an alcohol Straight chains

C2 to C20+

Fatty Acids

Differ in two ways Chain length

short- not usually in foods medium- milk fat, non-dairy creamers long- meat fats, olive oil, peanut oil very long- fish oils, some plant oils

Fatty Acids

Degree of saturation Partially determines health impact Chemical structure

saturated-all single bonds monounsaturated-one double bond polyunsaturated-two or more double

bonds

Essential Fatty Acids Linoleic Plant oils Omega 6 Rare deficiency Hormone-like Part of clotting

process and immune response

Linolenic Fish oils Omega 3 Rare deficiency Hormone-like Part of clotting

process and immune response

Linolenic -Omega 3 In the news Research on

preventing heart disease

Fish oil supplements?

Eat the fish!

Too much fish oil acts a blood thinner.

Dark meat fish or cold water fish.

Bass, cod, salmon

Phospholipids

Glycerol with 2 fatty acids plus choline or similar compound

Lecithin Supplement not needed Enough made in liver Emulsifiers Major part of cell membrane

2 fatty acids & 1 choline

Phospholipid formed

Sterols

Cholesterol Vitamin D Sex hormones Adrenocortical hormones

Plant sterols

Poorly absorbed Compete with CHOL absorption Can decrease CHOL absorption up

to 50% Subject of research & TV ads Phytoestrogens-hot topic in

women’s health

Sterols

Cholesterol made in liver, not essential part of cell membranes precursor of bile acids helps vitamin D be formed part of hormones

Cholesterol

Bile is made from cholesterol stored in gall bladder prepares fat for digestion after fat digestion,some is excreted

and some is reabsorbed CHOL in reabsorbed bile is reused Medications and dietary fiber is used

to bind bile-reduces total CHOL

Cholesterol

Some travels in bloodstream as part of lipoproteins

Can become trapped in arteries and contribute to heart disease

High CHOL and high fat diet increased risk of LDL elevation

Dietary Fat

Excessive intakes =obesity =diabetes mellitus =cancer =heart disease

Obesity

Imbalance Too many kcal in Not enough energy expenditure

Percentage of fat in diet varies Do not restrict fat until age 2 Gradually change diet to match

dietary guidelines during childhood

Cancer Fat may promote, but does not

cause cancer High fat diets linked to increased

risk for Colon and rectum Prostate Endometrium

More research needed

Cardiovascular Disease Leading cause of death Plaque development causes

increased incidence of blood clots Strongest diet connection

Too much saturated fat in the diet Polyunsaturated fats have both +/-

effects Monounsaturated fats more beneficial

Saturated Fat

Associated with serum CHOL elevation

Main dietary determinant of blood CHOL levels

Omega 3 fatty acids reduce CHOL most delay cancer development?

Polyunsaturated Fat

Associated with total serum CHOL reduction

Reduction LDL-C Shorter chained, unsaturated fats

are softer and melt more easily. Lard is hard.

Monounsaturated Fat

Associated with serum TG reduction

Maintenance of HDL-C Serum CHOL neutral

Fat substitutes

Instead of, not in addition Long term health effects not

known Simplesse Olestra Oatrim

Sources

Meats, nuts, seeds, olives, avocados

Ice cream Bakery products Salad dressing Milk Fried foods

Hydrogenated Fats

Unsaturated vegetable oils Hydrogen bonds have been added More stable products More solid products

Trans and CIS fatty acids

CIS fatty acid-naturally occurring bond H2 on same side of chain

Trans fatty acid-commercially made bond H2 on opposite sides makes more solid texture research says too much will raise

serum lipid levels limit to 5-10% of fat

Kcal and Grams Kcal from fat confusing for many

persons Count fat grams 20-30% of kcal from fat usually

appropriate X number of kcal by percent of kcal

from fat wanted Divide by 9

Dietary guidelines

Total fat <30% Saturated fat <10% Polyunsaturated <10% Monounsaturated <10% CHOL <300 mg New TLC diet: 200 mg CHOL, up to

35% fat if mostly monounsaturated